1. Field of the Invention
This invention relates to a non-rotatable pad type steering wheel and more particularly to a structure for attaching a non-rotatable column-side member for setting pad means non-rotatable.
2. Description of the Prior Art
Heretofore, there have been used planet and sun gears as non-rotatable members for a non-rotatable pad type steering wheel. That is, as shown in FIG. 15, a column-side sun gear 80 is directly attached to a column 81, and a boss 83 and other parts including a pad-side sun gear 84, planet members whose planet gears 85 engaging with both sun gears 80, 84 are attached to both ends of a planet shaft 85a and a bearing member 87 pivotally supporting the parts above are combined with a boss 88 and a boss plate 89 at the end of a steering shaft 82 so as to make non-rotatable pad means 90 attached to the pad-side sun gear 84 relative to a column 1.
As shown in FIG. 16, pad means (not shown) is made non-rotatable using column-side and pad-side members 97, 98 having a pair of guide grooves 95, 96 put in phase and a pair of slide members 99 movable along both the guide grooves 95, 96 in the axial direction of a steering shaft.
In those non-rotatable pad type steering wheels, the steering shaft 82 has a tapered portion 82a, which is fitted in a tapered bore 83a of the boss 83.
Consequently, when the boss 83 fitted at the end of the steering shaft 82 is tightened and fixed by a nut 91, there is produced a taper sink between the tapered bore 83a of the boss 83 and the tapered portion 82a of the steering shaft 82. For that reason, the fitting position of the steering wheel is out of fix and moreover the spacing in the axial direction between the pad-side non-rotatable members 84, 98 and the column-side non-rotatable members 80, 97 cannot be kept constant.
In the non-rotatable pad type steering wheel using the planet gear mechanism shown in FIG. 15, because the column-side planet gear 80 as a column-side non-rotatable member is fixed to the column 81, the aforementioned taper sink is produced when the steering wheel is fixed to the steering shaft 82. As a result, there are caused variations of spacing in the axial direction between the pad-side sun gear 84 fixed to the steering wheel side and the column-side sun gear 80, so that both the sun gears 80, 84 are not allowed to accurately engage with the plurality of planet gears 85. The problem is that the pad means 90 will become unsteady when the steering wheel is rotated.
Even if guide members 97, 98 and slide members 99 are used as shown in FIG. 16, there will also be caused variation of the spacing in the axial direction between the column-side guide member 97 and the pad-side guide member 98 because of the taper sink. Accordingly, the slide member 99 is not allowed to smoothly slide along the guide grooves 95, 96, so that the pad means will also become unsteady when the steering wheel is rotated.
Moreover, because the column-side non-rotatable member (column-side sun gear 80 or column-side guide member 97) is handled separated from the other parts of the steering wheel when it is transported or assembled, it has disadvantages in that troublesome care and much time are needed in handling and assembling.